In the automobile industry, it is known to use an engagement-disengagement release bearing to actuate the rotating diaphragm of a transmission from a translatable piston. To that end, the release bearing comprises a rolling bearing with rolling bodies, with a rotating ring designed to be in contact with the noses of the diaphragm, and a non-rotating ring that defines a central opening in which a maneuvering member is engaged secured to the piston or made up by a part thereof.
When such a release bearing is formed, it is essential for it not to be easy to disassemble, inasmuch as it is not always mounted in a corresponding housing or on a corresponding shaft as of its manufacture. Under these conditions, the inner and outer rings of such a release bearing may be subject to a separating force that is at least partially parallel to the rotation axis of the rolling bearing. When they are subjected to such a force, even with a relatively low intensity, the rings of the known release bearings tend to move axially away from one another. This may lead to the opening of the rolling chamber in which the rolling bodies are normally housed, and the loss of at least some of them.
Similar problems arise with the suspension release bearings and steering release bearings used in motor vehicles.
To offset these drawbacks, it is known to use an axial retaining seal, which is mounted between the two rings of the release bearing and which retains the outer ring or the inner ring when a separating force is applied on the release bearing. This seal further makes it possible to keep the grease near the rolling elements during operation and prevent the infiltration of outside particles in the rolling chamber.
Seals exist comprising a framework, which is crimped around the outer ring of the rolling bearing and which, as a result, forms an effective release bearing with respect to a pulling out force exerted on the rings. However, this type of seal increases the outer diameter of the rolling bearing, which is why seals anchored in the bore of the outer ring were developed.
In particular, FR-A-2,984,435 discloses a seal of this type, which is assembled within an engagement release bearing. This seal includes a rigid framework and a flexible fitting. The rigid framework comprises an edge, which is folded down radially toward a groove delimited on an inner radial surface of the outer ring. When the rings of the rolling bearing are subjected to a separating force, which is at least partially parallel to the axis of rotation of the rolling bearing, the rolling elements exert a reaction force on the seal and the framework of the latter deforms. The folded edge of the framework then becomes housed in the groove of the outer ring and forms a release bearing with respect to the reaction force, or pulling out force, exerted by the rolling bodies of the rolling bearing. However, the strength of this assembly is insufficient in case of significant separating force.